Foam producer



July 28, 1936.

WATER d I 9 ouPPLY [5 I STAB/LASER /0 J SUPPLY :5 6 fi I @Ill 73 -J INVENTOR Patented July 28, 1936 UNETED STATES FOAM PRODUCER Victor George William Gilbert, London, England,

asslgnor, by mesne assignments, to American- La France-Foamite Corporation, a corporation of New York Application July 18, 1934, Serial No. 735,745 In Great Britain September 8, 1933 3 Claims. (Cl. 261-121) The invention relates to the preparation of mechanically produced foam or so-called "air foam for fighting fire and. is in the nature of an improvement on the invention of my copending application Serial No. 674,868, filed June 8, 1933. The object is an apparatus by which the liquid and gaseous components are quickly and efliciently converted into foam without requiring to be beaten or otherwise treated and differs from the prior invention in that this result is achieved by introducing the bubble inflating medium (which may be and for convenience is referred to herein as air) into a suction-induced liquid stream and in a region of reduced flow velocity, as more particularly exemplified below, resulting in the continuous production of a more uniformly high quality of foam and throughout a wider range of capacities of the apparatus employed.

The accompanying drawing more or less diagrammatically illustrates a simple form of apparatus by which the method can be performed, Fig. 1 being a vertical section, Fig. 2 a section on the line 2-2 of Fig. 1 and Fig. 3 a reduced scale diagram of the entire apparatus.

The reference I indicates a pump by which the foam is directly discharged, as by way of a hose line 2. On its suction side the pump is connected, by a conduit indicated at large by the reference 3, with a source of supply of foam forming liquid, such as the tanks 4 and 5 containing water and saponine respectively, which supplies may be at an appropriate head to relieve the load on the pump or as convenience may require. At an appropriate point in the suction conduit there is established a relatively quiescent pool or region of reduced flow velocity, connected with, and maintained by, the liquid stream flowing under suction to the pump, and into such pool the air is admitted and directed in finely divided bubbleproducing form. In the apparatus illustrated this is accomplished as follows:

The liquid conduit 3 includes a riser or vertical section 6, the inlet 1 to which is located adjacent but above the lower end thereof, and the outlet 8 to the pump is located adjacent the upper end, thereby forming a sump or pool 9 in the bottom part of the riser. As will be understood, the water and saponine supplies are proportioned, as by the adjustment of the respective valves [0 and II, to produce the required mixture flowing to the pump through the riser, filling the sump 9.

The air intake comprises a vertical tube l2 which conveniently extends within the riser from a point above the normal liquid level to a point within the sump where it carries a plate or screen 13, preferably perforated as shown. At its upper end the tube is supported on a mouth piece fitting M which is threaded into the head of the riser, to enable plate l3 to be adjusted within the sump and also to vary the opening around its periphery.

The riser is itself supplied with an adjustable cap l5 for varying the volume of air admitted. In this preferred form the height of the riser, measuring the vertical travel of the air, is several times the diameter of conduit 3.

In operation, the air is drawn into the sump and, its upward flow being intercepted by plate [3, rises therefrom in finely divided bubble form into the stream flowing through the riser, expanding the liquid into foam. By appropriately correlating the rate of supply of air and liquid the former converts the latter into foam before reaching the pump and it is quite unnecessary to burden the latter with the work of forcing the foam through screens or subjecting it to other power-consuming treatment to refine it. It has been found that by introducing the air substantially in the manner indicated, rather than directly into the main stream flowing to the pump at its normal velocity, the stream of foam is singularly free from interruption as heretofore occasioned by the formation and intermittent passage of large air bubbles and the foam is of uniformly fine texture well-adapted for fire extinguishing purposes.

I claim:

1. Apparatus for producing and delivering fireextinguishing foam comprising in combination a pump, a source of supply of foam-forming liquid, a conduit connected therewith and with the suction side of the pump and into which liquid from said source is continuously drawn under pump suction, said conduit including a substantially vertical section, and means for admitting air into the lower part of such section.

2. Apparatus for producing and delivering fireextinguishing foam comprising in combination a pump, a source of supply of foam-forming liquid, a conduit connected therewith and with the suction side of the pump and into which liquid from said source is continuously drawn under pump suction, said conduit including a substantially vertical section with its outlet adjacent the upper end and its inlet adjacent but above the lower end thereof, and means for admitting air into the lower end of such section at a point below said inlet.

3. Apparatus for producing and delivering fire extinguishing foam, comprising in combination a .pump, a source of supply of foam-forming liquid,

a conduit connected therewith and with the suc tion side of the pump and into which liquid from said source is continuously drawn under pump suction, a sump connected with said conduit, a perforated screen member in the form of a partition substantially separating the sump from the conduit proper and means for admitting air into the sump below said screen.

VICTOR GEORGE WILLIAM GILBERT. 

